- Set PNG compression to maximum
- Don't upload thumbnail if it is not at least 10% smaller than  the
  original

Standard buttons are ordered in the right way and sometimes have an
icon.

Bug: https://matrix.to/#/%23nheko%3Anheko.im/%2476PZ2m6YftX8mqGIe9ettKbh_-pEYeVRQSJBfwFzWi0?via=pixie.town&via=matrix.org&via=matrix.flexinos.tech&via=half-shot.uk

fixes #878

This replaces the are-you-sure dialog and also shows up when using
/-commands.

Closes: https://github.com/Nheko-Reborn/nheko/issues/239

# Previous commits:
#   e390c398 Allow to specify reason for removed message
#   5949173b Add function to force focus on InputDialog input field
#   9482ac4e Allow explicit selection of SSO method
#   ab05e2d8 Mobile message input (#962)

# Previous commits:
#   5949173b Add function to force focus on InputDialog input field
#   9482ac4e Allow explicit selection of SSO method
#   ab05e2d8 Mobile message input (#962)
#   12a6da01 If you replace the txn id, replace a string the length of the txn id...

fixes #975

When setting the default font, actually set the default font. When
setting a different font, change the application font.

fixes #801
fixes #232
fixes #224

Achtung!

Anyone German in the room, or is it just me? ;3